Patentable/Patents/US-8471288
US-8471288

Group III nitride semiconductor light-emitting device including an auxiliary electrode in contact with a back surface of an n-type layer

PublishedJune 25, 2013
Assigneenot available in USPTO data we have
Inventorsnot available in USPTO data we have
Technical Abstract

A Group III nitride semiconductor light-emitting device includes a support, a p-electrode provided on the support, a p-type layer including a Group III nitride semiconductor and provided on the p-electrode, an active layer including a Group III nitride semiconductor and provided on the p-type layer, an n-type layer including a Group III nitride semiconductor and provided on the active layer, an n-electrode which is connected to the n-type layer, a first trench having a depth extending from a back surface of the p-type layer on a side of the p-electrode to reach the n-type layer, an auxiliary electrode which is in contact with a back surface of the n-type layer at a bottom of the first trench, but is not in contact with side walls of the first trench, and an insulating film which exhibits light permeability.

Patent Claims
18 claims

Legal claims defining the scope of protection. Each claim is shown in both the original legal language and a plain English translation.

Claim 1

Original Legal Text

1. A Group III nitride semiconductor light-emitting device, comprising: a support; a p-electrode provided on the support; a p-type layer comprising a Group III nitride semiconductor and provided on the p-electrode; an active layer comprising a Group III nitride semiconductor and provided on the p-type layer; an n-type layer comprising a Group III nitride semiconductor and provided on the active layer; an n-electrode which is electrically connected to the n-type layer; a first trench having a depth extending from a lower surface of the p-type layer on a side of the p-electrode to reach the n-type layer; an auxiliary electrode which is in contact with a lower surface of the n-type layer at a bottom of the first trench, but is not in contact with side walls of the first trench; an insulating film which exhibits light permeability and is provided to cover the auxiliary electrode and the bottom and side walls of the first trench; and a second trench which is provided in a region facing a portion of the auxiliary electrode in a direction perpendicular to a main surface of the device, and which has a depth extending from an upper surface of the n-type layer on a side opposite the side of the p-electrode to the auxiliary electrode, wherein the n-electrode comprises only a pad portion and is provided on a portion of the auxiliary electrode exposed through the second trench.

Plain English Translation

An LED light includes a support structure, a p-electrode on the support, a p-type semiconductor layer, an active light-emitting layer, and an n-type semiconductor layer. An n-electrode makes electrical contact with the n-type layer. A trench extends from the bottom of the p-type layer down to the n-type layer. An auxiliary electrode makes contact with the bottom surface of the n-type layer inside the trench, but not the trench walls. A light-permeable insulating film covers the auxiliary electrode and the trench's bottom and sides. A second trench exposes a portion of the auxiliary electrode on the opposite side of the device; the n-electrode (just a pad) sits on this exposed auxiliary electrode area.

Claim 2

Original Legal Text

2. A Group III nitride semiconductor light-emitting device according to claim 1 , wherein the device further comprises: a third trench which is provided in a region not facing the auxiliary electrode in the direction perpendicular to the main surface of the device, and which has a depth extending from the upper surface of the n-type layer on the side opposite the side of the p-electrode to the p-electrode; and a p-pad electrode which is provided on a portion of the p-electrode exposed through the third trench.

Plain English Translation

The LED from the previous description has a third trench extending from the top of the n-type layer (opposite the p-electrode side) down to the p-electrode, in a region that does *not* face the auxiliary electrode. A p-pad electrode sits on the portion of the p-electrode exposed by this third trench. Thus, in addition to the auxiliary n-electrode, there is a separate p-pad electrode making contact with the p-layer, accessed by another trench.

Claim 3

Original Legal Text

3. A Group III nitride semiconductor light-emitting device according to claim 1 , wherein a total area of the auxiliary electrode is greater than a total area of the n-electrode.

Plain English Translation

The LED described previously features an auxiliary electrode where the total surface area of this auxiliary electrode is larger than the total surface area of the n-electrode pad. In other words, the auxiliary electrode provides a larger contact area than the main n-electrode.

Claim 4

Original Legal Text

4. A Group III nitride semiconductor light-emitting device according to claim 1 , wherein the first trench and the auxiliary electrode comprise a wiring pattern, respectively.

Plain English Translation

The LED described previously includes a first trench and auxiliary electrode, and these elements are arranged in a wiring pattern. This means the trench and the auxiliary electrode form a conductive path or track on the device.

Claim 5

Original Legal Text

5. A Group III nitride semiconductor light-emitting device according to claim 1 , wherein the side walls of the first trench are inclined such that an area of a horizontal cross section of the first trench parallel to the main surface of the device is reduced with decreasing distance between the horizontal cross section and the n-type layer.

Plain English Translation

The LED light previously described includes a first trench whose sidewalls are sloped. The cross-sectional area of the trench decreases as you move closer to the n-type layer. Therefore, the trench is wider at the top (near the p-type layer) and narrower at the bottom (where it meets the n-type layer).

Claim 6

Original Legal Text

6. A Group III nitride semiconductor light-emitting device according to claim 1 , wherein the first trench and the auxiliary electrode comprise a surrounding wiring pattern which surrounds a periphery of a light emission region, respectively.

Plain English Translation

The LED described previously uses a first trench and an auxiliary electrode, arranged in a pattern that surrounds the light-emitting region of the device. This "surrounding wiring pattern" effectively encircles the area where light is generated.

Claim 7

Original Legal Text

7. A Group III nitride semiconductor light-emitting device according to claim 1 , wherein the auxiliary electrode comprises V/Al, Ti/Al, V/Au, Ti/Au, or Ni/Au.

Plain English Translation

The LED light previously described specifies that the auxiliary electrode is made of one of the following materials: V/Al (Vanadium/Aluminum), Ti/Al (Titanium/Aluminum), V/Au (Vanadium/Gold), Ti/Au (Titanium/Gold), or Ni/Au (Nickel/Gold).

Claim 8

Original Legal Text

8. A Group III nitride semiconductor light-emitting device according to claim 1 , wherein, as viewed from above, the auxiliary electrode encompasses the n-electrode.

Plain English Translation

The LED described previously has an auxiliary electrode that, when viewed from above, completely encompasses the n-electrode pad. The auxiliary electrode is larger and surrounds the n-electrode.

Claim 9

Original Legal Text

9. A Group III nitride semiconductor light-emitting device according to claim 1 , wherein the light-emitting device has a rectangular form, and wherein two pad portions are provided at diagonal positions of the light-emitting device having the rectangular form.

Plain English Translation

The LED light previously described is rectangular in shape, and it has two n-electrode pad portions that are positioned diagonally opposite each other on the rectangle.

Claim 10

Original Legal Text

10. A Group III nitride semiconductor light-emitting device according to claim 2 , wherein the light-emitting device has a rectangular form, and wherein two pad portions are provided at diagonal positions of the light-emitting device having the rectangular form.

Plain English Translation

The LED light, which includes (1) a support, (2) a p-electrode on the support, (3) a p-type semiconductor layer, (4) an active light-emitting layer, (5) an n-type semiconductor layer, (6) an n-electrode contacting the n-type layer, (7) a trench extending from the bottom of the p-type layer down to the n-type layer, (8) an auxiliary electrode contacting the n-type layer inside the trench, but not the trench walls, (9) a light-permeable insulating film covering the auxiliary electrode and the trench, (10) a second trench exposing a portion of the auxiliary electrode, and (11) a third trench extending from the top of the n-type layer down to the p-electrode plus a p-pad electrode on the exposed p-electrode area, is rectangular in shape and has two pad portions at diagonal positions.

Claim 11

Original Legal Text

11. A Group III nitride semiconductor light-emitting device according to claim 2 , wherein the light-emitting device has a rectangular form, and wherein the n-electrode and the p-pad electrode are disposed at diagonal positions of the light-emitting device having the rectangular form.

Plain English Translation

The LED light, which includes (1) a support, (2) a p-electrode on the support, (3) a p-type semiconductor layer, (4) an active light-emitting layer, (5) an n-type semiconductor layer, (6) an n-electrode contacting the n-type layer, (7) a trench extending from the bottom of the p-type layer down to the n-type layer, (8) an auxiliary electrode contacting the n-type layer inside the trench, but not the trench walls, (9) a light-permeable insulating film covering the auxiliary electrode and the trench, (10) a second trench exposing a portion of the auxiliary electrode, and (11) a third trench extending from the top of the n-type layer down to the p-electrode plus a p-pad electrode on the exposed p-electrode area, is rectangular and the n-electrode pad and the p-pad electrode are located at diagonal positions.

Claim 12

Original Legal Text

12. Group III nitride semiconductor light-emitting device according to claim 2 , wherein the support comprises a ceramic substrate.

Plain English Translation

The LED light, which includes (1) a support, (2) a p-electrode on the support, (3) a p-type semiconductor layer, (4) an active light-emitting layer, (5) an n-type semiconductor layer, (6) an n-electrode contacting the n-type layer, (7) a trench extending from the bottom of the p-type layer down to the n-type layer, (8) an auxiliary electrode contacting the n-type layer inside the trench, but not the trench walls, (9) a light-permeable insulating film covering the auxiliary electrode and the trench, (10) a second trench exposing a portion of the auxiliary electrode, and (11) a third trench extending from the top of the n-type layer down to the p-electrode plus a p-pad electrode on the exposed p-electrode area, has a support that is a ceramic substrate.

Claim 13

Original Legal Text

13. A Group III nitride semiconductor light-emitting device according to claim 6 , wherein the first trench and the auxiliary electrode comprise a grid-like wiring pattern.

Plain English Translation

The LED light, including a support structure, p/n-electrodes and semiconductor layers, a trench from the p-layer to the n-layer, an auxiliary electrode, an insulating film, where the first trench and the auxiliary electrode form a surrounding wiring pattern around the light-emitting area, includes a first trench and auxiliary electrode arranged in a grid-like wiring pattern.

Claim 14

Original Legal Text

14. A Group III nitride semiconductor light-emitting device according to claim 13 , wherein the light-emitting device has a rectangular form, and wherein two pad portions are provided at diagonal positions of the light-emitting device having the rectangular form.

Plain English Translation

The LED light, including a support structure, p/n-electrodes and semiconductor layers, a trench from the p-layer to the n-layer, an auxiliary electrode, an insulating film, where the first trench and the auxiliary electrode form a grid-like wiring pattern, is rectangular in shape, and two pad portions are located at diagonal positions.

Claim 15

Original Legal Text

15. A Group III nitride semiconductor light-emitting device according to claim 14 , wherein the support comprises an electrically conductive substrate and a current is supplied to the p-electrode through the electrically conductive substrate.

Plain English Translation

The rectangular LED light with diagonally placed pads and a grid-like wiring pattern for the trench and auxiliary electrode has a support that includes an electrically conductive substrate, and the p-electrode receives current through this conductive substrate.

Claim 16

Original Legal Text

16. A Group III nitride semiconductor light-emitting device according to claim 1 , further comprising gaps between the insulating film on side walls of the auxiliary electrode and the insulating film on the side walls of the first trench, the gaps being filled with the p-electrode.

Plain English Translation

The LED light previously described has gaps between the insulating film on the sidewalls of the auxiliary electrode and the insulating film on the sidewalls of the first trench, and these gaps are filled with the material of the p-electrode.

Claim 17

Original Legal Text

17. A Group III nitride semiconductor light-emitting device according to claim 2 , further comprising gaps between the insulating film on side walls of the auxiliary electrode and the insulating film on the side walls of the first trench, the gaps being filled with the p-electrode.

Plain English Translation

The LED light, which includes (1) a support, (2) a p-electrode on the support, (3) a p-type semiconductor layer, (4) an active light-emitting layer, (5) an n-type semiconductor layer, (6) an n-electrode contacting the n-type layer, (7) a trench extending from the bottom of the p-type layer down to the n-type layer, (8) an auxiliary electrode contacting the n-type layer inside the trench, but not the trench walls, (9) a light-permeable insulating film covering the auxiliary electrode and the trench, (10) a second trench exposing a portion of the auxiliary electrode, and (11) a third trench extending from the top of the n-type layer down to the p-electrode plus a p-pad electrode on the exposed p-electrode area, has gaps between the insulating film on the sidewalls of the auxiliary electrode and the insulating film on the sidewalls of the first trench, and these gaps are filled with the material of the p-electrode.

Claim 18

Original Legal Text

18. A Group III nitride semiconductor light-emitting device according to claim 13 , further comprising gaps between the insulating film on side walls of the auxiliary electrode and the insulating film on the side walls of the first trench, the gaps being filled with the p-electrode.

Plain English Translation

The LED light, including a support structure, p/n-electrodes and semiconductor layers, a trench from the p-layer to the n-layer, an auxiliary electrode, an insulating film, where the first trench and the auxiliary electrode form a grid-like wiring pattern, has gaps between the insulating film on the sidewalls of the auxiliary electrode and the insulating film on the sidewalls of the first trench, and these gaps are filled with the material of the p-electrode.

Classification Codes (CPC)

Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.

Patent Metadata

Filing Date

September 14, 2010

Publication Date

June 25, 2013

Want to explore more patents?

Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.

Citation & reuse

Analysis on this page is generated by Patentable — an AI-powered patent intelligence platform. AI-generated summaries, explanations, FAQs, and analysis may be reused with attribution and a visible link back to the canonical URL below. Patent abstracts and claims are USPTO public domain.

Cite as: Patentable. “Group III nitride semiconductor light-emitting device including an auxiliary electrode in contact with a back surface of an n-type layer” (US-8471288). https://patentable.app/patents/US-8471288

© 2026 Nomic Interactive Technology LLC. Machine-readable context available at /api/llm-context/US-8471288. See llms.txt for full attribution policy.

Group III nitride semiconductor light-emitting device including an auxiliary electrode in contact with a back surface of an n-type layer